Abstract: The present invention relates to a tire (100) for vehicle wheels comprising a tire component comprising a crosslinked elastomeric material obtained by crosslinking a crosslinkable elastomeric composition, wherein said elastomeric composition comprises a polymer blend comprising (a) 50 to 95 percent by weight of a first elastomeric polymer and (b) 5 to 50 percent by weight of a second elastomeric polymer based on the total weight of the polymer blend. The second elastomeric polymer (b) is obtainable by (i) anionic polymerization of at least one conjugated diene monomer and one or more a-olefin monomer(s) in the presence of a polymerization initiator in an organic solvent, and (ii) coupling the polymer chains obtained in (i) by a coupling agent. The second elastomeric polymer (b) has a weight-average molecular weight (Mw) in the range of 5,000-40,000 g/mol and a coupling rate of at least 50 percent by weight.

Abstract: The present invention relates to a tire (100) for vehicle wheels comprising a tire component comprising a crosslinked elastomeric material obtained by crosslinking a crosslinkable elastomeric composition, wherein said elastomeric composition comprises a polymer blend comprising (a) 50 to 95 percent by weight of a first elastomeric polymer and (b) 5 to 50 percent by weight of a second elastomeric polymer based on the total weight of the polymer blend. The second elastomeric polymer (b) is obtainable by (i) anionic polymerization of at least one conjugated diene monomer and one or more a-olefin monomer(s) in the presence of a polymerization initiator in an organic solvent, and (ii) coupling the polymer chains obtained in (i) by a coupling agent. The second elastomeric polymer (b) has a weight-average molecular weight (Mw) in the range of 5,000-40,000 g/mol and a coupling rate of at least 50 percent by weight.

Abstract: A process for the preparation of branched polybutadiene having a high content of 1,4-cis units which comprises polymerizing butadiene in the presence of at least one organic solvent, and in the presence of: a) a catalytic system prepared in situ including: (a1) at least one neodymium carboxylate, (a2) at least one alkyl compound of aluminum, (A3) at least one alkyl compound of aluminum containing at least one halogen atom, and b) at least one organic ester containing at least one halogen atom. Said branched polybutadiene having a high content of 1,4-cis units, depending on the branching degree and molecular weight distribution, can be advantageously used in various applications ranging from the modification of plastic materials [production, for example, of high impact polystyrene (HIPS)] to the production of tires, in particular the production of treads and/or of sidewalls of tires.

Abstract: A process for the preparation of branched polybutadiene having a high content of 1,4-cis units which comprises polymerizing butadiene in the presence of at least one organic solvent, and in the presence of: a) a catalytic system prepared in situ including: (a1) at least one neodymium carboxylate, (a2) at least one alkyl compound of aluminum, (A3) at least one alkyl compound of aluminum containing at least one halogen atom, and b) at least one organic ester containing at least one halogen atom. Said branched polybutadiene having a high content of 1,4-cis units, depending on the branching degree and molecular weight distribution, can be advantageously used in various applications ranging from the modification of plastic materials [production, for example, of high impact polystyrene (HIPS)] to the production of tyres, in particular the production of treads and/or of sidewalls of tyres.

Abstract: Process for the preparation of polybutadiene effected by the polymerization of butadiene in an aliphatic and/or cyclo-aliphatic solvent in the presence of a catalytic system prepared in situ which comprises: (i) a carboxylate of neodymium soluble in the process solvent containing a variable quantity of water, the H2O/Nd molar ratio ranging from 0.001/1 to 0.50/1; (ii) an alkyl compound of aluminum; (iii) an alkyl compound of aluminum in which at least one bond of Al consists of an Al—Cl bond; The total Al/Nd molar ratio ranging from 4/1 to 12/1, and the Cl/Nd molar ratio ranging from 2/1 to 6/1.

Abstract: Process for the preparation of polybutadiene effected by the polymerization of butadiene in an aliphatic and/or cyclo-aliphatic solvent in the presence of a catalytic system prepared in situ which comprises: (i) a carboxylate of neodymium soluble in the process solvent containing a variable quantity of water, the H2O/Nd molar ratio ranging from 0.001/1 to 0.50/1; (ii) an alkyl compound of aluminum; (iii) an alkyl compound of aluminum in which at least one bond of Al consists of an Al—Cl bond; The total Al/Nd molar ratio ranging from 4/1 to 12/1, and the Cl/Nd molar ratio ranging from 2/1 to 6/1.

Abstract: Process for the partial hydrogenation of random vinyl arene-conjugated diene copolymers in the presence of 2-methoxyethyl tetrahydrofuran as randomizing agent, comprising: reacting the random vinyl arene-conjugated diene copolymer, dissolved in a hydrocarbon solvent, with hydrogen, in the presence of a titanium complex and an alkylating agent, until the desired hydrogenation degree is obtained the above process being characterized in that the alkylating agent is selected from compounds having the general formula MgR1R2